Objective: To compare the diagnostic performance of modified Dixon (mDixon) turbo spin echo (TSE) T 2 weighted MRI and conventional T 1 weighted MRI in vertebral metastasis detection. Methods: Between September 2014 and October 2016, 33 patients with 68 metastases who had undergone whole-spine MRI were enrolled. The following sagittal image sets were evaluated: T 1WI, and mDixon TSE T 2 weighted water and fat images. Two radiologists independently evaluated each image-set for metastasis. The MR findings were compared with positron emission tomography-CT (PET-CT) scans. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each sequence. The diagnostic performance of each sequence was evaluated using receiver operating characteristic (ROC) curves. Results: Sensitivity, specificity, PPV and NPV for reviewer 1 were 83.8, 99.1, 89.1 and 98.6%, respectively, with T 1WI; 79.4, 98.8, 85.7 and 98.2%, respectively, with mDixon TSE T 2 weighted water imaging; and 86.8, 99.1, 89.4 and 98.8%, respectively, with mDixon TSE T 2 weighted fat imaging. For reviewer 2, the respective scores were 91.2, 99.2, 91.2 and 99.2%; 85.3, 99.5, 93.4 and 98.7%; and 89.7, 99.3, 92.4 and 99.1%. With PET-CT as the gold standard, the ROC curves of the three sequences showed no significant difference (all p > 0.05). Conclusion: The diagnostic performance of mDixon TSE T 2 weighted water and fat imaging was comparable to that of conventional T 1WI in the detection of vertebral metastases. Advances in knowledge: mDixon TSE T 2WI can be a good alternative to conventional T 1WI for detecting vertebral metastases.

Synthetic magnetic resonance imaging (MRI) allows reformatting of various synthetic images by adjustment of scanning parameters such as repetition time (TR) and echo time (TE). Optimized MR images can be reformatted from T1, T2, and proton density (PD) values to achieve maximum tissue contrast between joint fluid and adjacent soft tissue. To demonstrate the method for optimization of TR and TE by synthetic MRI and to validate the optimized images by comparison with conventional shoulder MR arthrography (MRA) images. Thirty-seven shoulder MRA images acquired by synthetic MRI were retrospectively evaluated for PD, T1, and T2 values at the joint fluid and glenoid labrum. Differences in signal intensity between the fluid and labrum were observed between TR of 500–6000 ms and TE of 80–300 ms in T2-weighted (T2W) images. Conventional T2W and synthetic images were analyzed for diagnostic agreement of supraspinatus tendon abnormalities (kappa statistics) and image quality scores (one-way analysis of variance with post-hoc analysis). Optimized mean values of TR and TE were 2724.7 ± 1634.7 and 80.1 ± 0.4, respectively. Diagnostic agreement for supraspinatus tendon abnormalities between conventional and synthetic MR images was excellent (κ = 0.882). The mean image quality score of the joint space in optimized synthetic images was significantly higher compared with those in conventional and synthetic images (2.861 ± 0.351 vs. 2.556 ± 0.607 vs. 2.750 ± 0.439; P < 0.05). Synthetic MRI with optimized TR and TE for shoulder MRA enables optimization of soft-tissue contrast.